Account without permissions to create SmartApp

Hello,

I am trying to create a smartapp (following this tutorial and this thread). Everything works fine until the point where I am redirected to the browser for logging in into my account. After I log in, the following appears:

Which means, my account doesn’t have this function available. I tried to look for a setting to enable this somehow, but couldn’t find any. Any idea why this might be happening?

Thank you in advance!